The present invention relates to telescoping slide assemblies having interconnected slide members including a stationary slide member, a chassis slide member, and an intermediate slide member positioned therebetween, and particularly to mechanisms for governing movement of a chassis slide member in a telescoping slide assembly. More particularly, the invention relates to multiple telescoping slide assemblies coupled together in parallel spaced-apart relation by a fixture attached to their respective intermediate slide members.
Telescoping slide assemblies are well known. Telescoping slide assemblies have been mounted to drawers or platforms to permit easy movement of equipment between a retracted position and an extended position. See, for example, Maxwell S. Fall U.S. Pat. No. 3,712,690.
In some situations, equipment may be housed in a cabinet during operation of the equipment and withdrawn from the cabinet for equipment maintenance or other purposes. For example, medical laboratories use a blood-shaking apparatus to shake blood contained in vials for various medical tests. The apparatus includes a vibrating machine which is designed to be moved into a cabinet to permit the blood-containing vials to be shaken inside the cabinet arid then to be moved out of the cabinet so that the shaken blood samples can be removed and the vibrating machine can be reloaded with fresh blood samples to be shaken. The blood-containing vials are shaken inside the cabinet in order to minimize contamination of surrounding areas in the event one of the blood-containing vials should break.
In the past, blood-shaking apparatus included a telescoping slide apparatus having a pair of separate slide assemblies. The slide assemblies are positioned in spaced-apart parallel relation and mounted to a cabinet support surface or cross member and arranged to engage the bottom of the vibrating machines. Lacking additional lateral support, that configuration permitted the vibrating machine to rock from side to side inside the cabinet, making a considerable amount of noise and potentially damaging the equipment and breaking blood-containing vials.
An additional problem became evident when the vibrating machines were extended from the cabinet. A lack of structural rigidity between the slide assemblies allowed the slide assemblies to flex differentially, wherein one slide assembly flexes along its longitudinal axis a little more than an adjacent slide assembly. When one slide assembly flexes more than its adjacent slide assembly, the equipment supported by the slide assemblies lacks a stable foundation and tends to lean toward the more flexible slide assembly.
An improved telescoping slide apparatus that is configured to move a blood-vibrating machine or any other shaking machine into and out of a cabinet so that rocking of the machine inside the cabinet is minimized would be a welcomed improvement over a conventional slide apparatus. Desirably, such an improved slide apparatus would include a pair of slide assemblies that are fortified and structurally rigid enough to minimize differential flexing of the slide assemblies that might induce a vibrating machine to lean over as it is being pulled out of its storage cabinet.
A simple mechanism is also needed to hold the chassis slide member in an extended position relative to the intermediate slide member once the telescoping slide assembly is pulled out to its extended position. What is needed is an improved slide assembly able to hold out the chassis slide member in an extended position relative to the intermediate slide member without requiring that extra parts or components be mounted on the slide assembly.
A conventional telescoping slide assembly can be worn out prematurely in certain cases when the chassis slide member comes into contact with certain ball bearings contained in raceways formed in a short ball bearing clip mounted to the surrounding intermediate slide member during extension and retraction of the slide members. This problem occurs more often if the telescoping slide assembly is mounted for movement in a horizontal plane rather than the more typical vertical plane. When conventional slide assemblies are mounted horizontally, the downward force of the load carried on the slide assembly pushes the ball bearings located in the ball bearing clip positioned between the chassis and intermediate slide members against their ball bearing raceways. This causes excessive wearing and/or deformation of the ball bearings. What is needed is a mechanism for preventing ball bearing deformation of the type just described to minimize any "drag" on the chassis slide member that might otherwise occur during extension and retraction of the telescoping slide assembly.
One object of the invention is to provide a stable telescoping slide apparatus having a pair of side-by-side bottom-mounted side assemblies that are connected together by a rigidifying plate without increasing the total vertical height of the telescoping slide apparatus. A low-profile telescoping slide apparatus that would be very rigid and stable yet thin enough to fit into a small space inside a cabinet would avoid problems associated with conventional telescoping slide apparatus.
Other objects of the invention are to provide an inner slide member that can be locked in a partly extended position relative to an outer slide member easily using a releasable frictional connection and that can move smoothly between extended and retracted positions without dislocating ball bearings used to support the inner slide member. A telescoping slide assembly including such features would be welcomed by users of slides.
According to one aspect of the present invention, a telescoping slide apparatus is provided for moving equipment between a retracted position and an extended position. The apparatus includes a plurality of bottom-mounted telescoping slide assemblies having stationary slide members, chassis slide members, and intermediate slide members interconnecting their respective stationary and chassis slide members. Means for connecting the intermediate slide members together in parallel spaced-apart relation is provided. The connecting means is formed to include aperture means for receiving an intermediate slide member therein.
In preferred embodiments, the connecting means includes a plate member having a plurality of longitudinally extending channels. Each channel is formed to include a longitudinally extending aperture or window for receiving an intermediate slide member. Thus the intermediate slide members, and therefore the slide assemblies, are held in parallel spaced-apart relation and positioned for attachment to a cabinet floor or cross member and the bottom of the equipment to be moved by the telescoping slide apparatus.
By mounting the intermediate slide members in the windows formed in the plate member, the plate member and the intermediate slide members extend and retract together as a unit. Each intermediate slide member fits in one of the windows formed in the plate member to "eliminate" the material thickness of the plate member. In other words, a plate member is used to rigidify the side-by-side pair of telescoping slide assemblies without adding any amount to the total vertical height (or thickness) of the slide apparatus. Advantageously, the plate apertures or windows are sized to receive existing slide assemblies. Thus, the connecting means provides lateral support and rigidity to the side-by-side pair of bottom-mounted telescoping slide assemblies without affecting the vertical height of the existing slide assemblies.
The plate member further includes a pair of parallel lateral edges extending along the length of the plate member and a skirt depending from each lateral edge. The longitudinally extending channels and the skirts combine to provide structural rigidity to the telescoping slide assemblies to reduce the differential flexing of the slide assemblies and the tendency of the equipment to lean when the slide assemblies are extended outside of the cabinet.
A plurality of rollers are loosely attached to each skirt to allow rotational and translational movement of the rollers relative to the plate member. The outer diameter of the rollers is substantially equal to a thickness dimension of the telescoping slide assemblies. When the slide assemblies are attached to the equipment and the cabinet surface, the rollers fit tightly between the cabinet surface and the bottom of the equipment, thereby providing lateral support to the equipment while the equipment is positioned inside the cabinet. These floating position rollers stabilize the equipment as it is moved in the cabinet yet float to allow for tolerances in the manufacture of the cabinet frame.
By providing a plate member with longitudinally extending channels having apertures or windows for rigidly receiving the intermediate slide members, and skirts depending from the lateral edges of the plate member, the present invention provides structural rigidity to minimize differential flexing of the telescoping slide assemblies and reduce the tendency for the vibrating machines to lean over to one side when extended from the cabinet. The intermediate slide members fit into apertures or windows formed in the plate member so that the total slide thickness or vertical height of the telescoping slide apparatus is not increased by the addition of the rigidifying plate member to the apparatus. By providing rollers coupled to the skirts, the present invention provides lateral support to minimize transverse oscillations when the equipment is retracted into the cabinet.
There is a certain vertical clearance between the vibrating machine and the floor of a conventional cabinet, with some of the vertical clearance taken up by conventional bottom-mounted telescoping slide assemblies. Thus, any improved telescoping slide apparatus should not have a vertical height greater than the vertical height of the conventional telescoping slide assemblies so that the new telescoping slide apparatus fits into the existing space between the vibrating machine and the cabinet floor and thus remains within the pre-existing vertical height clearance space. A rigidifying plate member in accordance with the present invention can be coupled to conventional telescoping slide assemblies to provide the necessary lateral support and structural rigidity to the conventional telescoping slide assemblies without altering the dimensions of the slide assemblies, thereby providing a stable, low vertical height telescoping slide assembly welcomed by owners of cabinets containing slide-in and slide-out vibrating equipment.
In other preferred embodiments, each slide member includes a pair of lateral edges formed to define bearing surfaces. The slide members are positioned so that the bearing surfaces of the chassis and stationary slide members cooperate with the bearing surfaces of the intermediate slide member to form bearing races. A plurality of ball bearings are positioned to move in the bearing races thus formed.
According to another aspect of the present invention, a releasable lock-out mechanism provides means for holding the chassis slide members in the extended position relative to the plate member. Advantageously, no extra components are added to the slide assembly to define this releasable lock-out mechanism. This releasable lock-out mechanism could be used in a wide variety of different slide assemblies. In one embodiment, each chassis slide member has an inner end that is deformed to provide flared tip ends that are extended laterally outwardly to contact and engage one of the ball bearings positioned in the bearing race formed between the chassis and intermediate slide member to create a releasable friction lock-out mechanism. In another embodiment, each intermediate slide member includes a stop member for blocking movement of the bearing race past a certain point during extension of the slide members and a detent for engaging between ball bearings positioned in the bearing race to create a releasable friction lock-out mechanism operable to hold the chassis slide member temporarily in an extended position relative to the intermediate slide member.
According to yet another aspect of the present invention, a skid pad is mounted to the intermediate slide member and positioned to lie under the inner chassis slide member when the telescoping slide assembly is mounted for movement in a horizontal plane. This skid pad replaces the conventional ball bearing clip often mounted at the outermost end of an intermediate slide member. Any downward load applied to the horizontal chassis slide member will now be transferred to the skid pad instead of to ball bearings in a conventional ball bearing clip engaging the chassis and intermediate slide members. This will help minimize any ball bearing deformation problem that might otherwise exist and should minimize drag forces applied by heavy loads to the chassis slide member during extension and retraction. This skid pad could be used in a wide variety of different slide assemblies.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of a preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.